The present invention relates to techniques for analyzing marks indicating an editing operation.
Suenaga, Y., "A Facsimile Based Text Editor Using Handwritten Mark Recognition," IJCAI-79, Proceedings of the Sixth International Joint Conference on Artificial Intelligence, Tokyo, Aug. 20-23, 1979, Vol. 2, pp. 856-858, describes a facsimile based text editor using handwritten mark recognition. As described in relation to FIG. 1, characters are placed according to ruled lines on manuscript paper. Marks are drawn directly on the manuscript paper or are drawn on other papers. Five kinds of marks are shown in FIG. 1, including a delete mark and a move mark. The move mark is defined as a line figure that consists of an arm and a loop, and a character string within the loop is extracted and inserted to the position indicated by the arm. During text editing, move marks are detected by searching along the center line of the space between lines and delete marks are detected by testing the inside of blocks. Text editing procedures and experimental results are described at pages 857-858 in relation to FIGS. 2, 3(a), and 3(b).
Suenaga, Y., and Nagura, M., "A Facsimile Based Manuscript Layout and Editing System by Auxiliary Mark Recognition," 5th International Conference on Pattern Recognition, Vol. 2, IEEE, 1980, pp. 856-858, describe an editor that uses handwritten mark recognition. Information for manuscript editing is input from a facsimile transmitter. Original texts, graphics, and auxiliary marks drawn on paper are input to the system as binary pictures. The marks are recognized to make a picture allocation list and a graphic command list. Handwritten alphanumerics in graphics are extracted and recognized by OCR. Fair copies of texts and graphics are constructed based on the lists and are output to a facsimile receiver. As shown and described in relation to FIG. 2, the system includes a text editing subsystem and a graphics editing subsystem.
The text editing subsystem, described at page 857, handles almost all kinds of texts having arbitrary size and format, including graphics patterns, estimating all parameters and instructions needed for editing from pictures of texts and marks. FIG. 3 shows marks, including a delete mark, a move mark, a copy mark, a pattern reservation mark, a pattern move mark, and a pattern copy mark. Marks are extracted and classified based upon topological and metric features. FIGS. 4(a) and 4(b) show an example of handwritten text editing.
The graphical editing subsystem, described at page 858, reforms line drawings using straight line or circular arc approximation and recognizes characters by OCR if marks specify to do so. FIG. 5 shows handwritten marks and seal marks. The handwritten marks include a "cutout-P" mark and a "cutout-C" mark. Marks are recognized by a procedure based on border following, to construct a mark parameters list for graphics. The picture of graphics is divided into portions--pixels surrounded by "cutout-P" marks are extracted to be stored in a binary picture file; pixels surrounded by "cutout-C" marks are extracted and sent to OCR to be recognized; and the remaining pixels are regarded as line drawings and expressed by a line drawings list (LDL). In accordance with the LDL, line drawings specified by certain marks are approximated by straight lines, circular arcs, or predetermined templates such as rectangles etc. A graphic command list is constructed and graphics are generated accordingly. An example is shown in FIGS. 6 and 1.